Three standard punctures are made with a lancet on the volar surface of the forearm under standard pressure, and the average time required for bleeding to cease from the puncture sites is measured.
(2) Sterile disposable lancets (2-2.5 mm blade with shoulder, which limits the depth of penetration).
(4) Filter paper
(1) A sphygmomanometer cuff is wrapped around the upper arm and inflated to 40 mm of Hg.
(2) The dorsal surface of the forearm is cleansed with 70% ethanol and allowed to dry.
(3) Three punctures are made (about 5 cm apart) in quick succession with a lancet (Superficial veins, and scars or bruises should be avoided).
(4) A stopwatch is started as soon as a puncture is made. One stopwatch is needed for each puncture.
(5) Blood oozing from the puncture wound is gently blotted with a filter paper at 15 seconds intervals. Avoid directly touching the edges of the wound.
(6) The timer is stopped when blood no longer stains the filter paper.
(7) Time required for bleeding to cease from all the three puncture wounds is noted. The average time is reported as the bleeding time.
(8) Sterile adhesive strip is applied over the puncture.
2-7 minutes. Majority of individuals have bleeding time less than 4 minutes. It should be reported in minutes or nearest half minute. If bleeding continues beyond 20 minutes, BT should be reported as >20 minutes and the test is discontinued.
(1) Thrombocytopenia: If platelet count is less than 1,00,000/ml, bleeding time should not be performed, as it will be prolonged. With a very low platelet count, bleeding may be difficult to control.
(2) Disorders of platelet function
(3) von Willebrand disease
(4) Disorders of blood vessels
1. Evatt BL, Gibbs WN, Lewis SM, McArthur JR. Fundamental Diagnostic Hematology: The Bleeding and Clotting Disorders (2nd ed), 1992. US Dept. of health and Human Services, Atlanta, Georgia and World Health Organization, Geneva, Switzerland.
2. Lewis SM, Bain BJ, bates I (Eds). Dacie and Lewis Practical Hematology (9th ed). London: Churchill Livingstone, 2002.
3. Provan D, Krentz A. Oxford Handbook of Clinical and Laboratory Investigations (2002). Oxford university Press. Oxford.